Computing the variance of the forecast error for the holt-winters seasonal models

This paper presents expressions for the variance of the forecast error for arbitrary lead times for both the additive and multiplicative Holt-Winters seasonal forecasting models. It is shown that even when the smoothing constants are chosen to have values between zero and one, when the period is greater than four, the variance may not be finite for some values of the smoothing constants. In addition, the regions where the variance becomes infinite are almost the same for both models. These results are of importance for practitioners, who may choose values for the smoothing constants arbitrarily, or by searching on the unit cube for values which minimize the sum of the squared errors when fitting the model to a data set. It is also shown that the variance of the forecast error for the multiplicative model is nonstationary and periodic.     

Specialized peptidoglycan of the bacterial endospore: the inner wall of the lockbox

A modified peptidoglycan (PG) wall is required for maintenance of spore core dehydration and the accompanying metabolic dormancy and heat resistance. Production of the spore PG depends on the cooperative expression of gene products within both the mother cell and forespore compartments of the sporangium. Structural elements that differentiate spore PG from vegetative cell PG include the presence of the modified sugar muramic-delta-lactam and a low level of peptide cross-links between the glycan strands. Detailed analyses of PG structure in dormant spores and in developing forespores of wild-type and mutant strains are providing data on factors required for introduction of these modifications and the importance of these structural elements in determining spore properties. Muramic-delta-lactam is not required for spore core dehydration but serves as a specificity factor for spore germination lytic enzymes. Cross-linking of spore PG can vary over a relatively wide range without significantly effecting spore core dehydration but does have an influence on the rate of spore germination and outgrowth. Future studies will examine how the two cells within the sporangium coordinate the production of this unique structure between themselves and how specific spore PG structural modifications are produced and participate in determining spore resistance properties.     

Effect of stress on choline acetyltransferase activity of the brain and the adrenal of the rat

Choline acetyltransferase (ChAT) activity was determined in cerebral cortex, hypothalamus, hippocampus, cerebellum, medulla oblongata, midbrain and adrenal gland of rats exposed to acute or chronic stress. The exposure of animals to acute immobilization and cold stress (4°C) for one hour resulted in a significant decline of ChAT activity in all brain regions examined except for the medulla oblongata. Moreover, the exposure to acute stress resulted in significant increase of the same enzyme in the adrenal gland. However, chronic exposure of animals to cold stress (4°C) for 7 days resulted in no significant changes of ChAT activity in all tissues examined except for a decline in the midbrain and an increase in the medulla oblongata. The administration of corticosterone (2.0 mg/kg) 1 h prior to sacrificing caused an effect similar to that of acute stress on ChAT activity in all brain regions except for the hypothalamus and the cerebellum. It was concluded from this experiment that stress-induced changes in the ChAT activity of specific brain regions might be mediated by the adrenal steroids.This work was supported by a grant from the National Aeronautics and Space Administration (NSG 2183 and NAG 2-411), a grant from the National Institutes of Health (NIH RR 0811) and a grant from the Division of Research Resources (NIH grant RR 03020).     

Effect of stress on choline acetyltransferase activity of the brain and the adrenal of the rat.

Choline acetyltransferase (ChAT) activity was determined in cerebral cortex, hypothalamus, hippocampus, cerebellum, medulla oblongata, midbrain and adrenal gland of rats exposed to acute or chronic stress. The exposure of animals to acute immobilization and cold stress (4 degrees C) for one hour resulted in a significant decline of ChAT activity in all brain regions examined except for the medulla oblongata. Moreover, the exposure to acute stress resulted in significant increase of the same enzyme in the adrenal gland. However, chronic exposure of animals to cold stress (4 degrees C) for 7 days resulted in no significant changes of ChAT activity in all tissues examined except for a decline in the midbrain and an increase in the medulla oblongata. The administration of corticosterone (2.0 mg/kg) 1 h prior to sacrificing caused an effect similar to that of acute stress on ChAT activity in all brain regions except for the hypothalamus and the cerebellum. It was concluded from this experiment that stress-induced changes in the ChAT activity of specific brain regions might be mediated by the adrenal steroids.     

Effects of tranylcypromine on the concentrations of some trace amines in the diencephalon and hippocampus of the rat

Summary Concentrations of 4 trace amines in diencephalon and hippocampus of the rat were measured by integrated-ioncurrent mass spectrometry after administration of the antidepressant drug, tranylcypromine. Much larger increases were observed for 2-phenylethylamine and tryptamine than for m- and p-tyramine.Financial support has been provided by the Medical Research Council of Canada, the Psychiatric Services Branch, Province of Saskatchewan, the Alberta Mental health Research Fund, and the Special Services and Research Committee, University of Alberta Hospital.Acknowledgments. The authors wish to thank Dr B.A. Davis for synthesizing the deuterated internal standards and Dr D.A. Durden for supervising the mass spectral analyses. Expert technical assistance was provided by Mr R.C. Mag-Atas and Ms D.G. Calverley. The advice and encouragement of Professors W. G. Dewhurst and A. A. Boulton are gratefully acknowledged.     

A rapid method for the verification of drug injection into the cerebral ventricular system of the rat

Summary A precise method for the injection of drugs into the cerebroventricular system of small animals used for experimentation is described. This method, based on the intraventricular pressure record, gives absolute certainty for the injection of a drug into a previously selected site and thus avoids the subsequent histological studies.     

The accuracy of aminoacylation--ensuring the fidelity of the genetic code

The fidelity of protein biosynthesis rests not only on the proper interaction of the messenger RNA codon with the anticodon of the tRNA, but also on the correct attachment of amino acids to their corresponding (cognate) transfer RNA (tRNA) species. This process is catalyzed by the aminoacyl-tRNA synthetases which discriminate with remarkable selectivity amongst many structurally similar tRNAs. The basis for this highly specific recognition of tRNA by these enzymes (also referred to as 'tRNA identity') is currently being elucidated by genetic, biochemical and biophysical techniques. At least two factors are important in determining the accuracy of aminoacylation: a) 'identity elements' in tRNA denote nucleotides in certain positions crucial for protein interactions determining specificity, and b) the occurrence in vivo of competition between synthetases for a particular tRNA which may have ambiguous identity.     

Paroxysmal discharges in the electroencephalogram of the El mouse

Summary The spike discharges in the EEG of the El mouse, a seizure-susceptible strain, were recorded during convulsive seizures. This fact provides evidence that those seizures are really epileptic convulsions.I thank Dr.K. Imaizumi and Dr.K. Nakano of National Institute of Health for their sharing the strain of El mouse to us and MissY. Nakamoto and Mr.N. Ozawa for their technical assistance and Mr.K. Moriyama for his care for the mice, and also thank Dr. H.Narabayashi for his criticism on this paper.     

Experimental investigation of the perceptibility of the artificial source for the dowsing agent. Progress report

Summary An artificial source for dowsing experiments is described. Investigations on the perceptibility of this source by turning on and off the water flow gives significant statistical results. The experiments for locating the source compared with blank experiments equally reveal perceptibility. An unexpected hysteresis in the reactions is observed when changing the source conditions in time and space. The behaviour of the sensitivity of the operator is deduced from many locating experiments.Acknowledgments. The author expresses his gratitude to the pharmaceutical company Hoffmann-La Roche for supporting this project, particularly to Prof. Dr A. Pletscher, the operators mentioned by the code names TR, RU, ER, ME, KO, RY and others, and all persons who contributed to this investigation.     

Effect of the ionic strength on the kinetic properties of the mitochondrial L-malate dehydrogenase

Increase of the ionic strength inhibits the catalytic activity of the mitochondrial MDH, reduces substrate inhibition and decreases the affinity of the substrates for the enzyme.     

Misuses of biology in the context of the paranormal

Public suspicion of science stems from science's challenging of perceptions and myths about reality, and a public fear of new technology. The result is a susceptibility to pseudoscience. In claiming that creation 'science' is as valid as evolution the creationists misquote scientists and seek to spread their own 'scientific' myths concerning a young age for the earth, an act of creation based on a particular literalist interpretation of the Christian Bible and a single worldwide flood. They use methods of debate and politics, rather than scientific research. A selection of their arguments is examined and the nature of the evidence for evolution is discussed. Problems with the creation 'science' model are noted. In the myth of the hundredth monkey phenomenon, original research is misquoted to denigrate scientific research and support sentimental ideas of paranormal events. The misuse of science is seen as damaging to society because it reduces the effective gathering and application of scientific information. However, pseudoscience provides a valuable guide to gaps in public scientific education.     

Sydney Chapman on the Layering of the Atmosphere: Conceptual Unity and the Modelling of the Ionosphere

Sydney Chapman is unanimously considered to have played a founding role in modern geomagnetism and to have opened up new lines of research in geophysics generally. Nevertheless, Chapman's conviction regarding the synthesis of the explanatory mechanisms of the atmosphere has gone practically unnoticed in the historiography of geophysics. This paper examines Chapman's contribution to ionospheric physics. It aims to understand Chapman's theory of ionospheric layer formation, and particularly its link to his theory of ozone formation. It deals first with the traits which characterized Chapman's personality, as a way of explaining—and even perhaps justifying— his quest for the integration and synthesis of geophysical knowledge. It then analyses Chapman's model of ionospheric layers and his suggestions regarding its use as an operational tool (without ontological connotations), before continuing with his account of the formation of the ozone layer, which seemed to constitute the missing link for understanding ionosphere layer formation. The paper concludes with Chapman's attempt to reconcile geomagnetic and radio evidence.     

Predicting the Direction of the Fed's Target Rate

Predicting the direction of central banks' target interest rates is important for various market participants. This paper advances procedures for predicting the direction of the federal funds target rate using a dynamic extension of the multinomial logit model. I find that the 6‐month Treasury bill spread relative to the federal funds rate, the unemployment rate and the real GDP growth rate have superior predictive content for the direction of the target a week to several months ahead. When these variables are employed, lagged target changes do not provide additional predictive power. This suggests that the apparent positive serial dependence of the target changes is due to the Fed's systematic response to autocorrelated macroeconomic variables. Copyright © 2010 John Wiley & Sons, Ltd.     

Drugs of the future: the hormone relaxin

The peptide hormone relaxin is emerging as a multi-functional factor in a broad range of target tissues including several non-reproductive organs, in addition to its historical role as a hormone of pregnancy. This review discusses the evidence that collectively demonstrates the many diverse and vital roles of relaxin: the homeostatic role of endogenous relaxin in mammalian pregnancy and ageing; its gender-related effects; the therapeutic effects of relaxin in the treatment of fibrosis, inflammation, cardioprotection, vasodilation and wound healing (angiogenesis) amongst other pathophysiological conditions, and its potential mechanism of action. Furthermore, translational issues using experimental models (to humans) and its use in various clinical trials, are described, each with important lessons for the design of future trials involving relaxin. The diverse physiological and pathological roles for relaxin have led to the search for its significance in humans and highlight its potential as a drug of the future. Received 12 December 2006; received after revision 12 February 2007; accepted 15 March 2007     

Hemicastration-induced changes in the electrophoretic pattern of some enzymes in the brain of the skink,Mabuya carinata

Summary Hemicastration in the skink induces change in the electrophoretic pattern of some enzymes like LDH, MDH, acid phosphatase and esterases.The authors wish to thank Prof. N.B. Krishnamurthy for his encouragment, UGC, New Delhi for their financial help to DTP and SM, and CSIR, New Delhi for MR.     

A comparative study of the innervation of the choroid plexus in amphibia

Summary The aminergic and cholinergic innervation of choroid plexuses in three species of amphibia was investigated. Plexuses of the Japanese toad and the bullfrog had poor innervation by adrenergic nerves of sympathetic origin, but in the clawed toad, these plexuses were heavily innervated by adrenergic axons from ganglion cells located in the plexus stroma. Nerve fibers positive for acetylcholinesterase were not found in the plexuses, except for a few fibers with very weak enzyme activity in the clawed toad.Acknowledgment. The authors are very grateful to Prof. T. Wasano (Professor emeritus of Kyushu University) for his encouragement and advice during the course of the present work.     

Determination of odour affinities based on the dose-response relationships of the frog's electro-olfactogram

Summary Electro-olfactograms (EOG's) recorded from the frog's olfactory epithelium for 11 substances were used to calculate dissociation constants which in turn serve as an index for the affinity between odorant and receptor site. These constants were calculated with and without a correction for the odour partition between water and air. For a homologous series of 7 n-alcohols these values decrease up to 1-heptanol. The dose-response relationships were based on the peaks of the EOG's since the peak/plateau-ratio was concentration-dependent for some of the substances.This work was supported by Z.W.O. grant number 12-24-12 of the Dutch Government.     

Bootstrap Replacement to Validate the Influence of the Economic Cycle on the Structure and the Accuracy Level of Business Failure Prediction Models

The aim of this study was to answer the question of how the economic cycle affects the stability and efficiency of business failure prediction models, using bootstrap replacement method for validation. We analyse 2228 Spanish small and medium‐sized enterprises for the period 2001–2009, and divide it into three different phases of the economic cycle (growth, crisis, recession). We find that the structure and the ability of business failure prediction models are different according to the economic cycle. These findings are relevant for the debate on the most suitable financial ratios when developing business failure prediction models and to pose their accuracy level in these prediction models. Copyright © 2015 John Wiley & Sons, Ltd.     

Effect of diabetes on the enzymes of the cholinergic system of the rat brain

Choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activities were determined in several brain regions of normal and streptozotocin-induced diabetic rats. The diabetic rats exhibited significant increase in ChAT activity (p less than 0.05) in all brain regions studied except for the cortex and the midbrain. Meanwhile, the diabetes condition was associated with significant increase (p less than 0.05) in AChE activity of the bulbus olfactorius, medulla oblongata and cerebellum. These data suggest that uncontrolled diabetes is associated with significant alterations in the brain cholinergic systems.